Electrical loads in various power management applications are driven by switching circuits. Examples of the power management applications can include, but are not limited to, direct current to direct current (DC-DC) converters and Class D amplifiers. A switching circuit employs semiconductor switches with high switching frequencies that are driven by a driver circuit.
During the operation of the driver circuit, a switching noise (which can be caused, for example, by package inductances or by printed circuit board inductances) can be induced, thereby causing phenomenon such as supply bounce and ground bounce in an operating voltage of the switching circuit. Such noise-induced phenomenon can further lead to breakdown of the switches. The supply bounce and the ground bounce can be caused in higher proportions for low cost packages, such as, for example, a thin quad flat package and a small quad flat package. Furthermore, in addition to the undesirable phenomenon of supply bounce and the ground bounce, the switching noise can also create reliability and performance issues for the switching circuit, the driver circuit and other circuits sharing a common power supply. The switching noise can couple onto circuits present on-chip through a substrate and also couple onto the other circuits present on-board sharing the power supply with the switching circuit. Furthermore, in addition, the switching noise can also cause a higher level of electromagnetic interference (EMI) thus violating emission specification associated with the switching circuit.
In addition to the foregoing, in certain scenarios the switching noise, and in turn the supply bounce and ground bounce, can be reduced if the driver circuit is operated at a low speed. However, operation of the driver circuit at low speeds can cause degradation in efficiency of the switching circuit due to an increase in switching loss. Moreover, the switching noise, as well as the reliability and performance issues in the switching circuit, can also be reduced if high voltage devices are used to reduce the supply bounce and ground bounce. However, such high voltage devices can increase manufacturing and product costs due to mask addition, while the switching noise is still associated with the circuits sharing the common power supply.